L-kynurenine induces NK cell loss in gastric cancer microenvironment via promoting ferroptosis.

BACKGROUND: Natural killer (NK) cells play a major role in body's fighting against various types of cancers. Their infiltration in the tumor microenvironment (TME) of gastric cancer (GC) are significantly decreased, which has been reported as a robust prognostic marker. However, the causes leading to NK cells loss in GC TME remains poorly understood. METHODS: We constructed a non-contact co-culturing system and humanized xenograft tumor mice model to detect the influence of GC microenvironment on NK-92 or primary human NK cells viability by flow cytometry. Then through using the specific inhibitors for different types of cell death and examining the surrogate markers, we confirmed ferroptosis in NK cells. Inspired by the accidental discoveries, we constructed a NK-92 cell strain with high expression of GPX4 and treated the humanized xenograft tumor mice model with the NK-92 cells. RESULTS: We found L-KYN, mainly generated through indoleamine 2, 3-dioxygenase (IDO) from GC cells, impaired NK cells viability in TME. Further analysis revealed L-KYN induced ferroptosis in NK cells via an AHR-independent way. Moreover, we found NK cells with higher GPX4 expression showed resistance to L-KYN induced ferroptosis. Based on this, we generated GPX4 over-expressed NK-92 cells, and found these cells showed therapeutic potential towards GC. CONCLUSIONS: Our study revealed a novel mechanism to explain the decline of NK cell number in GC TME. Notably, we also developed a potential immunotherapy strategy, which might be beneficial in clinical treatment in the future.

Porous Covalent Organic Framework Based Hydrogen-Bond Nanotrap for the Precise Recognition and Separation of Gold.

Utilizing weak interactions to effectively recover and separate precious metals in solution is of great importance but the practice remains a challenge. Herein, we report a novel strategy to achieve precise recognition and separation of gold by regulating the hydrogen-bond (H-bond) nanotrap within the pore of covalent organic frameworks (COFs). It is found that both COF-HNU25 and COF-HNU26 can efficiently capture AuIII with fast kinetics, high selectivity, and uptake capacity. In particular, the COF-HNU25 with the high density of H-bond nanotraps exhibits an excellent gold uptake capacity of 1725 mg g-1 , which is significantly higher than that (219 mg g-1 ) of its isostructural COF (COF-42) without H-bond nanostrap in the pores. Importantly, the uptake capacity is strongly correlated to the number of H-bonds between phenolic OH in the COF and [AuCl4 ]- in water, and multiple H-bond interactions are the key driving force for the excellent gold recovery and reusability of the adsorbent.

MTMR2 promotes invasion and metastasis of gastric cancer via inactivating IFNγ/STAT1 signaling.

BACKGROUND: The aberrant expression of myotubularin-related protein 2 (MTMR2) has been found in some cancers, but little is known about the roles and clinical relevance. The present study aimed to investigate the roles and clinical relevance of MTMR2 as well as the underlying mechanisms in gastric cancer (GC). METHODS: MTMR2 expression was examined in 295 GC samples by using immunohistochemistry (IHC). The correlation between MTMR2 expression and clinicopathological features and outcomes of the patients was analyzed. The roles of MTMR2 in regulating the invasive and metastatic capabilities of GC cells were observed using gain-and loss-of-function assays both in vitro and in vivo. The pathways involved in MTMR2-regulating invasion and metastasis were selected and identified by using mRNA expression profiling. Functions and underlying mechanisms of MTMR2-mediated invasion and metastasis were further investigated in a series of in vitro studies. RESULTS: MTMR2 was highly expressed in human GC tissues compared to adjacent normal tissues and its expression levels were significantly correlated with depth of invasion, lymph node metastasis, and TNM stage. Patients with MTMR2high had significantly shorter lifespan than those with MTMR2low. Cox regression analysis showed that MTMR2 was an independent prognostic indicator for GC patients. Knockdown of MTMR2 significantly reduced migratory and invasive capabilities in vitro and metastases in vivo in GC cells, while overexpressing MTMR2 achieved the opposite results. MTMR2 knockdown and overexpression markedly inhibited and promoted the epithelial-mesenchymal transition (EMT), respectively. MTMR2 mediated EMT through the IFNγ/STAT1/IRF1 pathway to promote GC invasion and metastasis. Phosphorylation of STAT1 and IRF1 was increased by MTMR2 knockdown and decreased by MTMR2 overexpression accompanying with ZEB1 down-regulation and up-regulation, respectively. Silencing IRF1 upregulated ZEB1, which induced EMT and consequently enhanced invasion and metastasis in GC cells. CONCLUSIONS: Our findings suggest that MTMR2 is an important promoter in GC invasion and metastasis by inactivating IFNγ/STAT1 signaling and may act as a new prognostic indicator and a potential therapeutic target for GC.

NETO2 promotes invasion and metastasis of gastric cancer cells via activation of PI3K/Akt/NF-κB/Snail axis and predicts outcome of the patients.

Aberrant expression of neuropilin and tolloid-like 2 (NETO2) has been observed during the progression of some human carcinomas. However, the expression pattern and clinical relevance of NETO2 in gastric cancer (GC) remain to be elucidated. In this study, we found that NETO2 expression was higher in GC tissues compared with paired non-cancerous tissues. Moreover, the expression of NETO2 was positively correlated with clinical stage, invasion depth, lymph node metastasis, and tumor size, but inversely correlated with overall and disease-free survival rates. Cox regression analysis identified NETO2 as an independent prognostic indicator for GC patients. Overexpression of NETO2 facilitated migration and invasion of GC cells in vitro and metastasis in vivo in association with induction of epithelial-mesenchymal transition. Conversely, knockdown of NETO2 had the opposite effects. Mechanistically, silencing NETO2 reduced the phosphorylation of PI3K, AKT, and NF-κB p65 as well as the expression of Snail, whereas NETO2 overexpression achieved the opposite results. Furthermore, we identified TNFRSF12A as a mediator for NETO2 to activate PI3K/AKT/NF-κB/Snail axis. Collectively, our results demonstrate that NETO2 promotes invasion and metastasis of GC cells and represents a novel prognostic indicator as well as a potential therapeutic target in GC.

Long-term oncologic outcomes of a randomized controlled trial comparing laparoscopic versus open gastrectomy with D2 lymph node dissection for advanced gastric cancer.

BACKGROUND: Laparoscopy-assisted gastrectomy is a feasible and safe procedure for treating advanced gastric cancer in terms of short-term outcomes. However, concern about long-term oncologic outcomes has limited the adoption of laparoscopy-assisted gastrectomy for advanced gastric cancer. METHODS: We launched a prospective randomized controlled trial comparing laparoscopic and open gastrectomy with D2 lymph node dissection for locally advanced gastric cancer to evaluate long-term oncologic feasibility. The 5-year overall survival, disease-free survival, and tumor recurrences have been determined on an intention-to-treat basis. RESULTS: Between January 2010 and June 2012, a total of 328 patients with preoperative clinical stage T2-4aN0-3M0 gastric cancer were enrolled in the trial. We excluded 6 patients with unresected tumor, and the remaining 322 patients were randomized to the laparoscopic group (162 patients) or the open group (160 patients) for radical surgery. One patient in laparoscopy-assisted gastrectomy and 4 patients in open gastrectomy were lost to follow-up immediately after discharge, leaving 317 patients (161 in laparoscopy-assisted gastrectomy and 156 in open gastrectomy) eligible for long-term analysis. The 5-year overall survival rate was 49.0% in the laparoscopic group and 50.7% in the open group, and the 5-year disease-free survival rate was 47.2% and 49.6% in the 2 groups, respectively. Kaplan-Meier curves for overall survival and disease-free survival showed no differences between the 2 groups. There was no difference in the 5-year tumor recurrence rate between the 2 procedures. CONCLUSION: Laparoscopy-assisted gastrectomy can provide comparable long-term survival without an increase in recurrence and metastasis in treating advanced gastric cancer.

Interleukin-23 promotes the migration and invasion of gastric cancer cells by inducing epithelial-to-mesenchymal transition via the STAT3 pathway.

Chronic inflammation is associated with all stages of cancer development. Moreover, a proinflammatory microenvironment resulted from chronic inflammation is considered to be an essential component of cancer. Interleukin-23 (IL-23) is a general proinflammatory factor; and is involved in tumor-associated inflammation in gastric cancer (GC). However, the direct effect of IL-23 on GC cells has been rarely reported. The aim of the study was to clarify the direct role of IL-23 in regulating GC progression, and to identify the underlying mechanism. In this study, Positive expression of IL-23R was observed in GC tissues and cell lines by using immunohistochemistry or immunofluorescence. In western blots, the expression of IL-23R was higher in GC tissues compared with adjacent normal tissues. Furthermore, IL-23R positive GC tissues were closely related with larger tumor size and worse T stage and clinical stage. By performing in vitro experiments, we found that IL-23 binding to its receptor promoted the migration and invasion of BGC-823 cells in vitro. Moreover, IL-23 induced the activation of STAT3 and epithelial-to-mesenchymal transition (EMT) in BGC-823 cells. Knocking down STAT3 in BGC-823 cells attenuated the effect of IL-23 on EMT and cell migration and invasion. Taken together, our study has firstly demonstrated the positive expression of IL-23R in human GC tissues and cell lines. IL-23 binding to its receptor promotes the migration and invasion of GC cells by inducing EMT through the STAT3 signaling pathway. This work provides a new mechanism for the oncogenic role of IL-23 on GC progression.

Short-term surgical outcomes of a randomized controlled trial comparing laparoscopic versus open gastrectomy with D2 lymph node dissection for advanced gastric cancer.

BACKGROUND: Laparoscopy-assisted gastrectomy (LAG) has gained acceptance as one of the best treatments for early gastric cancer. However, the application of LAG with D2 lymph node dissection in patients with locally advanced gastric cancer (AGC) remains controversial. METHODS: We launched a prospective randomized controlled trial comparing laparoscopic and open gastrectomy with D2 lymph node dissection for locally AGC to evaluate technical safety and oncologic feasibility. The postoperative morbidity and mortality rates were based on the modified intention-to-treat analysis. RESULTS: Between January 2010 and June 2012, a total of 328 patients with preoperative clinical stage T2-3N0-3M0 gastric cancer were enrolled in the trial. Six patients with unresected AGC were excluded, and the remaining 322 patients were randomized to the laparoscopic group (162 patients) or the open group (160 patients) for radical surgery. All patients underwent D2 lymph node dissection including 18 (5.59%) proximal gastrectomies, 196 (60.87%) distal gastrectomies, and 108 (33.54%) total gastrectomies. Six patients (3.70%) in the LAG group were converted to open procedures. The overall complication rate was 11.72% in the LAG group and 14.38% in the open group (P = 0.512). No mortality occurred in either group. CONCLUSIONS: The short-term results of the current study suggest that LAG with D2 lymph node dissection is a safe and feasible procedure in treating patients with locally AGC in experienced centers.

miR-320a modulates cell growth and chemosensitivity via regulating ADAM10 in gastric cancer.

MicroRNAs (miRNAs) may function as tumor suppressor or onco­miRNAs and have critical roles in the pathogenesis of gastric cancer (GC). The exact function and mechanism of miRNA (miR)­320a in GC remains to be elucidated. The present study performed gain­ and loss­of­function analyses by transfecting cells with mimics or inhibitors and subsequently performing colony formation, proliferation and cisplatin­sensitivity assays. Additionally, in vivo xenograft models were also performed. Bioinformatics algorithms, luciferase reporter activity assay and western blotting were used to predict the potential target of miR­320a. Additionally, the effect of knockdown or overexpression of ADAM metallopeptidase domain 10 (ADAM10) on cell growth and chemosensitivity was examined. The expression of miR­320a and ADAM10 was also determined in primary tumors. The present study revealed that the expression of miR­320a was reduced in GC cells and ectopic miR­320a expression significantly inhibited cell growth in vitro and in vivo and enhanced the sensitivity of GC cells to cisplatin. ADAM10 was a direct target of miR­320a in GC. Knockdown of ADAM10 attenuated the proliferative ability of GC cells, and increased the sensitivity of GC cells to cisplatin. The upregulated ADAM10 accelerated cell growth rate and reduced the cisplatin­sensitivity of cells. Clinically, a significantly negative correlation was identified between the expression of miR­320a and mRNA levels of ADAM10 in tumors. The findings of the present study suggested that miR­320a may function as a tumor suppressor in GC progression and potential therapeutic strategies for GC may be based on the miR­320a/ADAM10 axis.

The role of obestatin in Roux-en-Y gastric bypass surgery in the obese, type 2 diabetes Zucker rat.

AIMS: Roux-en-Y gastric bypass (RYGB) is a novel therapy for diabetes and the exact mechanisms of this procedure remain unclear. Obestatin is an important gut hormone. We aimed to explore the role of obestatin in the therapeutic mechanism of RYGB. METHODS: Twenty obese Zucker rats and twenty Wistar rats were randomly assigned to two groups: RYGB and sham surgery. We evaluated plasma obestatin and insulin levels pre- and post-RYGB. Additionally, obestatin expression levels in the gastrointestinal tract were assessed using immunohistochemical staining. RESULTS: In Zucker rats, plasma obestatin and insulin levels gradually increased after RYGB. At post-operation week 7, plasma levels of obestatin were higher in the RYGB group than the sham operation group, and fasting plasma insulin levels were significantly increased the in RYGB group compared with the sham operation group. Furthermore, we observed a positive relationship between obestatin and insulin plasma levels. Among 10 zucker rats, high expression of obestatin was only seen in the jejunum of 2 rats before the operation; however, high expression of obestatin was seen in the Roux limb of 8 rats and in the ileum of 7 rats after RYGB. The expression of obestatin was significantly higher in the intestine in the RYGB group than the sham operation group postoperatively. CONCLUSIONS: We propose that obestatin maybe a potential mediator to improve glucose homeostasis after RYGB. The increase of obestatin secretion may be an important mechanism through which RYGB alleviates obesity and type 2 diabetes mellitus.

The role of obestatin in roux-en-Y gastric bypass-induced remission of type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is a complex and multifactorial disease that is generally characterized by insulin resistance and loss of ß-cell function that develops in adulthood. To date, more than 6% of the world's population is affected by T2DM. The main treatments of T2DM are dietary and lifestyle changes. However, only dependent on behaviour modification and oral hypoglycemics, many patients are unable to maintain glycemic control. Emerging evidence indicates that up to 80% of patients with T2DM undergoing Roux-en-Y gastric bypass (RYGB) experience complete remission of their T2DM and the majority of remissions occur almost immediately following the operation. Obestatin is a 23-amino-acid peptide, which is not only thought to suppress food intake and decrease gastric emptying but also found to exert survival effects in pancreatic ß cells, increase glucose-stimulated insulin secretion, and reduce insulin resistance and inflammation. In addition, some researchers demonstrated that obestatin is a nutritional marker reflecting body adiposity and insulin resistance. Although results from previous studies were conflicting, the peripheral blood concentrations of obestatin were changed after RYGB. Therefore, regulation of obestatin level may be another mechanism for RYGB-induced remission of T2DM. In this article, we review briefly the effect of RYGB on T2DM in humans and offer an overview of the published data on the effects of RYGB on obestatin level in patients with T2DM. Furthermore, the possible roles of obestatin in the remission of T2DM following RYGB are also reviewed. Copyright © 2015 John Wiley & Sons, Ltd.

A hybrid registration-based method for whole-body micro-CT mice images.

The widespread use of whole-body small animal in vivo imaging in preclinical research has proposed the new demands on imaging processing and analysis. Micro-CT provides detailed anatomical structural information for continuous detection and different individual comparison, but the body deformation happened during different data acquisition needs sophisticated registration. In this paper, we propose a hybrid method for registering micro-CT mice images, which combines the strengths of point-based and intensity-based registration methods. Point-based non-rigid method using thin-plate spline robust point matching algorithm is utilized to acquire a coarse registration. And then intensity-based non-rigid method using normalized mutual information, Halton sampling and adaptive stochastic gradient descent optimization is used to acquire precise registration. Two accuracy metrics, Dice coefficient and average surface distance are used to do the quantitative evaluation. With the intra- and intersubject micro-CT mice images registration assessment, the hybrid method has been proven capable of excellent performance on micro-CT mice images registration.

Dependency of magnetic microwave absorption on surface architecture of Co20Ni80 hierarchical structures studied by electron holography.

To design and fabricate rational surface architecture of individual particles is one of the key factors that affect their magnetic properties and microwave absorption capability, which is still a great challenge. Herein, a series of Co20Ni80 hierarchical structures with different surface morphologies, including flower-, urchin-, ball-, and chain-like morphologies, were obtained using structure-directing templates via a facile one-step solvothermal treatment. The microwave reflection loss (RL) of urchin-like Co20Ni80 hierarchical structures reaches as high as -33.5 dB at 3 GHz, with almost twice the RL intensity of the ball- and chain-like structures, and the absorption bandwidth (<-10 dB) is about 5.5 GHz for the flower-like morphology, indicating that the surface nanospikes and nanoflakes on the Co20Ni80 microsphere surfaces have great influences on their magnetic microwave absorption properties. Electron holography analysis reveals that the surface nanospikes and nanoflakes could generate a high density of stray magnetic flux lines and contribute a large saturation magnetization (105.62 emu g(-1) for urchin-like and 96.41 emu g(-1) for flower-like morphology), leading the urchin-like and flower-like Co20Ni80 to possess stronger microwave RL compared with the ball-like and chain-like Co20Ni80 alloys. The eddy-current absorption mechanism µ''(µ')(-2)(f)(-1) is dominant in the frequency region above 8 GHz, implying that eddy-current loss is a vital factor for microwave RL in the high frequency range. It can be supposed from our findings that different surface morphologies of magnetic hierarchical structures might become an effective path to achieve high-performance microwave absorption for electromagnetic shielding and stealth camouflage applications.

In vivo quantitative evaluation of vascular parameters for angiogenesis based on sparse principal component analysis and aggregated boosted trees.

To solve the multicollinearity issue and unequal contribution of vascular parameters for the quantification of angiogenesis, we developed a quantification evaluation method of vascular parameters for angiogenesis based on in vivo micro-CT imaging of hindlimb ischemic model mice. Taking vascular volume as the ground truth parameter, nine vascular parameters were first assembled into sparse principal components (PCs) to reduce the multicolinearity issue. Aggregated boosted trees (ABTs) were then employed to analyze the importance of vascular parameters for the quantification of angiogenesis via the loadings of sparse PCs. The results demonstrated that vascular volume was mainly characterized by vascular area, vascular junction, connectivity density, segment number and vascular length, which indicated they were the key vascular parameters for the quantification of angiogenesis. The proposed quantitative evaluation method was compared with both the ABTs directly using the nine vascular parameters and Pearson correlation, which were consistent. In contrast to the ABTs directly using the vascular parameters, the proposed method can select all the key vascular parameters simultaneously, because all the key vascular parameters were assembled into the sparse PCs with the highest relative importance.

High expression of CX3CL1/CX3CR1 axis predicts a poor prognosis of pancreatic ductal adenocarcinoma.

BACKGROUND: CX3CL1 is a member of the chemokine family, and its receptor, CX3CR1, is expressed in pancreatic ductal adenocarcinoma. However, it is unclear whether there is a correlation between the expression of CX3CL1/CX3CR1 axis and the prognosis of patients with pancreatic ductal adenocarcinoma. METHODS: Tissue microarray and immunohistochemistry were used to study the expression of CX3CL1 and CX3CR1 in 105 specimens of pancreatic ductal adenocarcinoma. We analyzed a relationship between patients' clinicopathological parameters and overall survival to the expression level of the CX3CL1/CX3CR1 axis using standard statistical analysis. RESULTS: The expression of CX3CL1 and CX3CR1 (77.1 and 66.7 %, respectively) was clearly increased in areas of malignancy compared with peritumoral areas. We did not find any correlation between CX3CL1 and CX3CR1 expression with clinical or pathological data. Patients' overall survival was clearly worse with the combined high expression of CX3CL1 and CX3CR1. Patients with a high CX3CL1 expression tumor had a significantly shorter overall survival. High CX3CR1 expression was an independent negative prognosis factor. CONCLUSION: We propose that the expression level of CX3CL1/CX3CR1 axis could provide clinical prognostic value, and the next steps should be to further investigate the mechanism by which CX3CL1 and its receptor impact survival in pancreatic ductal adenocarcinoma.

[Study on activated protein C resistance and disordered coagulation in patients with myeloproliferative neoplasms].

OBJECTIVE: To study the correlation of activated protein C (APC) resistance, coagulation factors and inhibitors abnormality and JAK2V617F mutation burden in patients with myeloproliferative neoplasms (MPN). METHODS: The APC resistance was defined as the ratio of activated partial thromboplastin time (APTT) in the presence and absence of APC, i.e. APC sensitivity ratio (APCsr). Plasma protein C (PC), protein S (PS), prothrombin (FII), factor V (FV), factor VIII levels and CD11b expression on neutrophils were measured. The percentage of mutated JAK2V617F allele (V617F%) was evaluated by real time polymerase chain reaction (qRT-PCR). RESULTS: Expression of CD11b on neutrophils was significantly elevated in MPN patients compared with that of the control group. APCsr, PS and FV levels were reduced in patients with MPN. The APCsr level was decreased mainly in patients with thrombosis and JAK2V617F mutant burden higher than 75%. APCsr was not only positively correlated with PS levels but also inversely correlated with JAK2V617F allele burden in JAK2V617F mutant gene carriers. CONCLUSION: The neutrophil was activated and PS, FV level were reduced in MPN patients. The APCsr level was decreased and the occurrence of relatively acquired APC resistance was found in MPN patients with thrombosis. The APCsr is correlated with the PS level and JAK2V617F mutational furden.

[Immune tolerance induction in a severe hemophilia A patient with inhibitor].

OBJECTIVE: To explore the immune tolerance induction (ITI) in a severe hemophilia A patient with inhibitor, and to improve the therapeutic efficacy for patient. METHODS: The FVIII:C was assayed by one-stage method and FVIII antibody by Bethesda method. Mutation screening of FVIII gene intron 22 inversion was performed using LD-PCR. RESULTS: FVIII gene intron 22 inversion was detected in this patient. Clinical tolerance to FVIII was successfully induced after administration of the ITI regimen combined with immunosuppression. A fall of inhibitor titer from 8 BU to 0 BU after treatment for 3 months, and in vivo FVIII recovery (> 66%) was normalized. The patient had no bleeding episode in the following 6 months. CONCLUSION: This is the first case report on successful immune tolerance induction therapy in Chinese hemophilia A patient. ITI is the most effective therapy for hemophilia A with inhibitor.

[Expression of human factor IX in retrovirus-transfected human umbilical cord tissue derived mesenchymal stem cells].

The purpose of this study was to investigate the expression of human Factor IX (hFIX) in retrovirus-transfected human umbilical cord tissue derived mesenchymal stem cells (hUCT-MSCs). The pLEGFP-N1-hFIX vector was generated by cloning a 3.0 kb Bgl II-BamH I fragment from the pIRES2-EGFP-hFIX plasmid containing the hFIX cDNA and part of intron 1 of hFIX in pLEGFP-N1 vector. The retroviral supernatants were produced from the Phoenix packaging cell line and then infected the hUCT-MSCs. After selection with G418 for 10 day, the expression of FIX was detected by ELISA and Western blot. The biological activity of FIX was determined by the clotting assay employing human Factor IX-deficient plasma. The results showed that compared with the activity of pooled human normal plasma (100%), transduced cells produced biologically active hFIX with 100-130% activity in two-day culture supernatant and expressed hFIX at levels of 2.68 +/- 0.36 microg/10(6) cells/24 hours after G418 selection for 10 days. The secretion of hFIX into culture supernatant was also confirmed by Western blot analysis. It is concluded that genetically modified hUCT-MSCs can express biologically active hFIX and thus serve as an efficient drug delivery vehicle carrying hFIX used as a way of somatic gene therapy for hemophilia B.